The present invention relates to apparatus for installing and disengaging the well-known twist lock air fitting (also known as a Chicago fitting). The twist lock air fitting has first and second interlocking members each having at least two claws to attach to locking tabs on the opposite interlocking member. The twist lock air fitting also uses grommets on each interlocking member to assure an air tight seal of the first and second interlocking members.
Of course, the whole reason for using the twist lock air fitting is to allow the installation and disengagement of the coupling at will. Nevertheless, the twist lock air fitting has, previous to the present invention, been extremely difficult to install and disengage.
The difficulty of installing and disengaging the twist lock air fitting stems from the fact that installation and disengagement require that the first and second interlocking members of the twist lock air fitting be pressed tightly together so that the sealing grommets are tightly compacted while simultaneously rotating each of the first and second interlocking members in opposite rotations about their central axes in order to allow their claws to clear the locking tabs on the locking flanges.
The prior art of installing and disengaging the twist lock air fitting known to the applicant has not been able to discover or invent an acceptable method or apparatus that will safely and conveniently install and disengage the twist lock air fitting. The only attempts of the prior art have been to attach a pair of pliers to each of the first and second interlocking members together with shaving the sealing grommets to reduce their protrusion from the first and second interlocking members and/or filing down the locking tabs to reduce or eliminate the need for simultaneous pressure between the first and second interlocking members during the opposite rotations of the first and second interlocking members. This method, at worst, creates an extremely dangerous condition where the first and second interlocking members can explosively come apart because they are not effectively locked together, or, at best, causes air or water leaks between the shaved sealing grommets. Either or both of these methods and apparatus are totally unacceptable and yet are the only methods and apparatus offered by the prior art.
The present invention offers an apparatus which enables the user to conveniently and easily create sufficient compressive force between the first and second interlocking members so that their claws can clear the locking tabs on each interlocking member together with allowing simultaneous opposite rotations of the first and second interlocking members about their central axes to complete installation or disengagement of the twist lock air fitting.